CN110568567A

CN110568567A - optical fiber printed circuit board assembly surface cleaning and roughening

Info

Publication number: CN110568567A
Application number: CN201810575121.7A
Authority: CN
Inventors: 陈涛; 董成杰; 姜进; 施廷; 余韶军; 刘有吉
Original assignee: Finisar Corp
Current assignee: Finisar Corp
Priority date: 2018-06-06
Filing date: 2018-06-06
Publication date: 2019-12-13
Also published as: US20190377141A1; US11555973B2; US20200371301A1; US10816741B2

Abstract

The present disclosure generally relates to a printed circuit board or printed circuit board assembly for fiber optic communications, in one example, a method may include coupling at least one optoelectronic component to a surface of the printed circuit board, the method may include laser treating the surface of the printed circuit board to form a laser roughened area on the surface of the printed circuit board, the method may include coupling an optical component to the printed circuit board at the laser roughened area on the surface of the printed circuit board.

Description

Optical fiber printed circuit board assembly surface cleaning and roughening

Technical Field

The present disclosure generally relates to printed circuit boards or printed circuit board assemblies for fiber optic communications. In particular, the present disclosure relates to modification of the surface of a printed circuit board to facilitate the manufacture of optoelectronic assemblies, which may result in improved optoelectronic assemblies incorporating aspects described herein.

Background

A Printed Circuit Board (PCB) mechanically supports and electrically connects electrical components using electrically conductive couplings, such as traces, pads, and/or other features etched from one or more layers of electrically conductive material, such as copper, attached to one or more layers of a non-conductive substrate. The components are typically soldered to the PCB in order to electrically connect the components to the PCB and mechanically secure the components to the PCB. PCBs may be used in optoelectronic assemblies that convert electrical signals to optical signals, optical signals to electrical signals, or both. Opto-electronic components may be used, for example, for fiber optic communications to exchange data at increased rates.

In an optoelectronic assembly employing a PCB, electrical and optical components may be coupled to the PCB. However, PCB assemblies having electrical and optical components may present various manufacturing challenges that may need to be addressed to efficiently produce optoelectronic assemblies.

the claimed subject matter is not limited to implementations that solve the above disadvantages or that operate only in environments such as those described above. This background is merely provided to illustrate examples in which the present disclosure may be utilized.

Disclosure of Invention

The present disclosure generally relates to modification of a surface of a Printed Circuit Board (PCB) to facilitate fabrication of optoelectronic assemblies, which may result in improved optoelectronic assemblies incorporating aspects described herein.

In one non-limiting example, a method may include coupling at least one optoelectronic component to a surface of a PCB. The method may include laser treating a surface of the PCB to form a laser roughened area on the surface of the PCB. The method may include coupling an optical component to the PCB at a laser roughened area on a surface of the PCB.

the optical component may be attached at a coupling area on a surface of the PCB, and the laser roughened area may be positioned at least partially or completely within the coupling area. The optical component may be coupled to the PCB using an adhesive, such as an epoxy or other suitable adhesive. The optical component may be optically coupled or optically aligned with the optoelectronic component.

The laser treatment may remove at least a portion of a layer of the PCB. The laser treatment may increase the roughness of the surface of the PCB. In certain aspects, the laser treatment may increase the arithmetic mean deviation of the evaluation profile of the surface of the PCB by at least 0.1. The laser treatment may remove or decompose contaminants on the surface of the PCB. The laser treatment may improve the coupling of the optical component to the PCB by increasing the roughness of the surface of the printed circuit board and/or removing contaminants from the surface of the printed circuit board.

In some aspects, the method may include applying a solder mask to a surface of the printed circuit board prior to applying the laser. The laser treatment may remove at least a portion of a layer of the PCB and/or at least a portion of a solder mask on the PCB.

The optical component may be a lens optically coupled or aligned with the opto-electronic component. The laser roughened area may at least partially surround the optoelectronic component in a plane defined by the PCB. After the optical component is coupled to the PCB, the optical component may at least partially enclose the optoelectronic component. After the optical component is coupled to the PCB, the optoelectronic component may be hermetically sealed between the PCB and the optical component.

The method may include attaching at least one electrical component to a surface of the printed circuit board. The laser may be applied for a sufficient duration to decompose the surface of the PCB such that the laser roughened area is visually perceptible. The method may include visually inspecting a surface of the printed circuit board to determine whether a portion of the printed circuit board has been laser processed.

In another non-limiting example, an optoelectronic assembly can include a printed circuit board, at least one optoelectronic component coupled to a surface of the printed circuit board, and an optical component attached to a laser roughened area of the surface of the printed circuit board. The optical component may be attached to the laser-roughened area by an adhesive. The optical component may be optically coupled or optically aligned with the optoelectronic component. The optical component may be a lens or another optical component at least partially enclosing the optoelectronic component.

The laser roughened area of the surface of the printed circuit board may be rougher than the remaining area of the surface of the printed circuit board. The laser roughened area of the surface of the printed circuit board may have a greater arithmetic mean deviation of the evaluation profile than the remaining area of the surface of the printed circuit board. The difference between the laser roughened area and the rest of the surface of the printed circuit board can be visually perceived.

The optoelectronic assembly may include a solder mask on a surface of the printed circuit board. The solder mask may not be present at the laser roughened area of the surface of the printed circuit board. The laser roughened area may surround the optoelectronic component in a plane defined by the printed circuit board. The optical component may be a lens at least partially enclosing the optoelectronic component. The lens may be optically aligned with the optoelectronic component. The lens may hermetically seal the optoelectronic component.

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary does not identify key features or essential features of the claimed subject matter, and is not intended to be used to determine the scope of the claimed subject matter.

Drawings

FIG. 1A is a schematic top view of an exemplary Printed Circuit Board Assembly (PCBA);

FIG. 1B is a schematic top view of a portion of the PCBA of FIG. 1A;

FIG. 1C is another schematic top view of a portion of the PCBA of FIG. 1A;

FIG. 2A is a cross-sectional schematic view of a portion of the PCBA of FIG. 1A;

FIG. 2B is a cross-sectional schematic view of a portion of the PCBA of FIG. 1A;

FIG. 3 is a flow diagram of an exemplary method of forming a PCBA;

FIG. 4 is a flow diagram of another exemplary method of forming a PCBA;

FIG. 5A is a schematic top view of the PCBA of FIG. 1A with optical components; and

Figure 5B is a side view schematic diagram of the PCBA of figure 5A.

Detailed Description

The present disclosure generally relates to printed circuit boards or printed circuit board assemblies for fiber optic communications. A component containing a Printed Circuit Board (PCB) may be referred to as a Printed Circuit Board Assembly (PCBA). In particular, the present disclosure relates to modification of the surface of a PCB to facilitate the manufacture of optoelectronic components, which may result in improved optoelectronic components incorporating aspects described herein.

The PCB may be applied in an optoelectronic assembly configured for fiber optic communications. An optoelectronic assembly employing a PCB may include electrical and optical components coupled to the PCB. However, PCB assemblies having electrical and optical components may present various manufacturing challenges that can affect the efficient and effective production of optoelectronic assemblies.

For example, certain optical components, such as lenses, may be optically aligned with other optical components. Thus, the optical components may need to be positioned and attached to the PCB more accurately than the electrical components. Furthermore, it may be impractical to attach the optical component to the PCB with solder. Thus, the optical component may be attached to the PCB in other ways. However, coupling the optical components to the PCB in a cost-effective and robust manner creates additional challenges.

In some cases, it may be desirable to mechanically couple the optical component to a surface of the PCB, for example, using an adhesive or other suitable attachment method. For example, in some conventional methods of mechanically coupling an optical component to a surface, the PCB may not be processed. The untreated PCB includes an uncleaned, generally smooth surface. If the surface of the PCB is contaminated, the optical component may not be sufficiently bonded with the PCB. Furthermore, if the surface of the PCB is contaminated when the optical component is bonded to the PCB, the bond generated between the PCB and the optical component may be relatively weak. In this case, the bond may break over time, for example during subsequent processing of the PCB to form an optoelectronic assembly. Furthermore, the weaker bond may break after the optoelectronic component is fabricated, for example, during operation of the optoelectronic component. Furthermore, in this case, the optoelectronic component may fail prematurely due to weak bonding caused by a substantially smooth surface of the PCB or contaminants left on the surface of the PCB during manufacturing.

some PCBA implement via technology (THT). THT refers to a mounting method for attaching an electrical component using a lead wire extending from the electrical component. The leads are inserted into holes formed in the PCB and soldered to pads on the opposite side of the PCB. Other PCBA's implement Surface Mount Technology (SMT). SMT is a mounting method that mounts or places components directly onto the surface of a PCB. SMT components are typically smaller than THT components because SMT components have smaller leads or no leads at all. In general, SMT speeds up the manufacturing process compared to THT. However, the use of SMT in some cases increases the risk of defects due to component miniaturization and dense packing of components on a PCB. In this case, it may also be more difficult to detect defects (e.g., contaminants or defective bonds). Although both SMT and THT can be implemented in a variety of situations, SMT has largely replaced THT in the manufacture of PCBA.

For example, during SMT or THT processing, the surface of the PCB may become contaminated during normal manufacturing processes. When the PCB is formed, contaminants such as solder, oil, dust, adhesive, or other contaminants may be deposited on the surface of the PCB. These contaminants can be difficult to detect during and after manufacture and can result in weak bonds that are also difficult to detect. For example, using a microscope or using other detection methods, the contaminant may not be visible to the human eye. Therefore, it may be difficult to determine whether the surface of the PCB is contaminated prior to bonding. Furthermore, it can be difficult to remove contaminants that are not visible or can not be detected, and to determine whether the contaminants were successfully removed.

Even if the surface of the PCB does not include contaminants, in some cases, the PCB may not be suitable for attaching components to its surface. For example, the surface of the PCB may be relatively smooth. The adhesive may not adhere as well to a smooth surface as to a rough surface. Some PCBs may include a solder mask, which is a thin lacquer-like polymer layer applied to the surface of the PCB. Solder masks may be used to protect conductive traces on a PCB from oxidation and to prevent or reduce undesired electrical connections between adjacent conductive traces located relatively close to each other. The solder mask may also be relatively smooth and the adhesive may form a relatively poor bond with the solder mask, for example, when coupling the optical component to a PCB.

Accordingly, the present disclosure includes configurations that modify the surface of the PCB to remove contaminants (e.g., clean the surface) and/or increase the roughness of the surface. In particular, a laser may be used to remove contaminants on the surface of the PCB. Further, the laser may be used to remove a portion of the PCB (e.g., a portion of a layer of the PCB, an entire layer of the PCB, or more than one layer of the PCB). In addition, a laser may be used to increase the roughness of the surface of the PCB.

Aspects described herein may improve bonding between a PCB and a component (e.g., an optical component or other component) attached to the PCB using, for example, an adhesive or other suitable attachment method. In particular, the bonding between the PCB and the component may be improved as the laser removes contaminants from the surface of the PCB and/or increases its roughness. This may increase the strength of the bond between the PCB and the optical component, which in turn may reduce the likelihood of the bond breaking during and after manufacture. Furthermore, assemblies according to the concepts described herein are less likely to fail prematurely due to bond fracture between the PCB and the attachment component.

In addition, the laser may visibly modify the surface of the PCB, making it easier to determine whether contaminants have been removed from a particular area on the PCB and/or whether that area has been roughened. For example, the laser may change the color and/or texture of the lased surface of the PCB. In particular, the color and/or texture of the surface may be different in areas, as all or a portion of the layers of the PCB may be removed by the laser. This configuration may also facilitate positioning of the component to be coupled to the PCB, as the visible modified surface may indicate the location where the component should be attached to the PCB.

Using a laser to modify the surface of the PCB may avoid damaging components coupled to the PCB. In particular, some components (e.g., electrical or other components) may be attached to the PCB before the laser is applied to the surface of the PCB. The laser may be precisely controlled to apply the laser in a specific area on the surface of the PCB. The precise control of the laser may avoid components already coupled to the PCB from being damaged. The use of a laser may provide some advantages over other methods of removing contamination. For example, other methods for removing contaminants from a PCB, such as solvent cleaning, plasma cleaning, etc., may risk damaging components on the PCB.

Reference will now be made to the drawings and specific language will be used to describe the various aspects of the disclosure. The drawings and description are to be regarded as illustrative in nature and not as restrictive. Other aspects may be apparent from the disclosure, including the claims, or may be learned by practice.

Fig. 1A is a schematic top view of an example of PCBA 100. PCBA100 may comprise a PCB that includes an insulative substrate 102 and a surface 118. Various components, such as electrical components 104a-e, may be positioned on substrate 102 and mechanically coupled to substrate 102. The electrical components 104a-e may be electrically coupled by conductive couplings 106 a-e. The conductive couplings 106a-e can be traces, pads, and/or other features etched from one or more layers of conductive material, such as copper. Electrical components 104a-e may be soldered to electrically and mechanically couple to PCBA 100.

PCBA100 may comprise a single layer configuration or a multi-layer configuration. If PCBA100 is a single-layer PCB, PCBA100 may include a layer of insulating substrate with conductive coupling elements positioned on one or both sides of the insulating substrate. If PCBA100 is a multi-layer PCB, PCBA100 may include multiple layers of insulating substrate, and conductive couplings may be positioned on and/or between the multiple layers.

In some configurations, PCBA100 may include a solder mask, which is a layer applied to surface 118 of PCBA 100. The solder mask may be a layer on surface 118 or a layer proximate to surface 118 of PCBA 100. The solder mask may protect portions of the PCBA100, such as the conductive couplings 106 a-e. For example, the solder mask can protect the conductive couplings 106a-e from oxidation and prevent undesired electrical connections between adjacent conductive couplings (e.g., 106a and 106d) that are positioned relatively close to each other. The solder mask can be relatively smooth and the adhesive can form a relatively poor bond with the solder mask, such as when a component is attached to PCBA 100.

In some cases, a solder mask may be applied to PCBA100 using a masking or screen printing technique. The solder mask may be applied as an epoxy liquid to PCBA100 by screen printing a pattern. Additionally or alternatively, the solder mask may be applied using any suitable technique, such as a Liquid Photoimageable Solder Mask (LPSM) or a dry film photoimageable solder mask (DFSM). Once applied, the solder mask may be cured, for example, using a thermal or ultraviolet curing method. Any suitable method, such as photolithography, may be used to form the openings in the solder mask.

PCBA100 may include opto-electronic components 108. In such a configuration, PCBA100 may be included in an optoelectronic assembly for fiber optic communication, although the concepts described herein may be implemented in any suitable PCBA. The opto-electronic components 108 may include components related to the conversion of electrical signals to optical signals, optical signals to electrical signals, or both electrical signals to optical signals and optical signals to electrical signals. For example, the optoelectronic component 108 may include a receiver or receiver array configured to receive an optical signal and generate a corresponding electrical signal. In another example, the optoelectronic component 108 may include an emitter or an array of emitters configured to receive an electrical signal and generate a corresponding optical signal.

The opto-electronic components 108 may include or may be coupled to components related to the optical transmitter and receiver. Some examples of such components may include amplifiers (e.g., trans-impedance amplifiers, limiting amplifiers, etc.), Clock and Data Recovery (CDR) circuits, digital signal processing circuits, drivers, digital-to-analog converter (DAC) circuits, modulators, or other suitable components. In some configurations, these components may be included in electrical components 104 a-e.

As described above, opto-electronic components may include electrical components 104a-e and/or opto-electronic components 108 coupled to PCBA 100. The optoelectronic assembly may also include an optical component optically coupled or aligned with the optoelectronic component 108. The optical components may include lenses, filters, collimators, mirrors, polarizers, or any other suitable component used in optoelectronics. The optical components may be configured to perform optical functions such as directing, focusing, collimating, modulating, multiplexing, or demultiplexing optical signals to and from the opto-electronic component 108.

At least some of the optical components may be mechanically coupled to PCBA 100. As shown, the optical component can be mechanically coupled to PCBA100 at coupling area 110. Coupling area 110 may correspond to the size and/or shape of an optical component to be coupled with PCBA 100. In the illustrated configuration, the coupling region 110 is rectangular with rounded corners and annular (e.g., rectangular ring-shaped). Coupling area 110 may correspond to a rectangular optical component to be mechanically coupled to PCBA100 and optically coupled to opto-electronic component 108. In other configurations, coupling region 110 may be any suitable shape or size, and the configuration of coupling region 110 may depend on the shape and size of the optical component. In the example shown, the optical components may include lenses, but any suitable components may be coupled to PCBA100 in accordance with the concepts described in the present disclosure.

PCBA100 may include laser roughened area 112. Laser-roughened area 112 may correspond to the size and/or shape of coupling area 110 or an optical component to be coupled with PCBA 100. In the illustrated configuration, the laser-roughened area 112 is rectangular and annular (e.g., rectangular annular) with rounded corners, the laser-roughened area 112 corresponding to the coupling area 110. As shown, the laser-roughened area 112 may be positioned entirely within the coupling area 110, although other configurations may be implemented. In other configurations, the laser-roughened area 112 may be any suitable shape or size, and the configuration of the laser-roughened area 112 may depend on the shape and size of the coupling area 110, the optical component, or both the coupling area 110 and the optical component.

As described in further detail below, laser-roughened area 112 may be formed by a laser applied to surface 118 of PCBA100 (e.g., laser treating surface 118 of PCBA 100). A laser may be used to remove a portion of PCBA100 to form laser roughened area 112. In particular, the laser may be used to remove a portion of a layer of PCBA100, an entire layer of PCBA100, or more than one layer of PCBA 100. For example, a laser may be used to remove about 1 to 30 micrometers (μm) of PCBA100 (e.g., to remove a depth or height of a portion). In some configurations, the power, intensity, and/or wavelength of the laser may be selected to remove a desired amount of PCBA 100. Additionally or alternatively, the laser may be repeatedly applied to a given area to remove additional layers or portions of PCBA 100. Accordingly, whenever a laser is applied to an area on PCBA100 (e.g., laser roughened area 112), the extra portion may be removed.

The power, intensity, and/or wavelength of the laser used to form the laser-roughened area 112 can be selected to be sufficiently high to increase the roughness of the surface. Additionally or alternatively, the power, intensity, and/or wavelength of the laser used to form laser-roughened area 112 may be selected to be sufficiently high to remove or decompose contaminants without damaging PCBA100 and/or components coupled to PCBA100, such as electrical components 104a-e and opto-electronic components 108. The desired power, intensity, and/or wavelength of the laser may depend on the material included in the PCB (e.g., a layer of the PCB), the material of the contaminant, the material of the component coupled to the PCB, or any suitable combination thereof. In one example, the laser may be an ultraviolet laser, e.g., a laser that emits electromagnetic radiation in the ultraviolet wavelength range. In some cases, the ultraviolet wavelengths may include wavelengths between 100 nanometers (nm) and 400 nm. In some configurations, the laser may be a 355nm wavelength laser, although other suitable configurations may also be implemented. Additionally or alternatively, in some configurations, the laser may include a laser power of 3 watts (W).

the laser-roughened area 112 of the surface 118 of the PCBA100 may be rougher than the remaining area of the surface 118 of the PCB. The laser roughened area 112 of the surface 118 of the PCB may have a larger arithmetic mean deviation of the evaluation profile than the remaining area of the surface 118 of the PCB. The difference between the laser roughened area 112 and the rest of the surface 118 of the PCB may be visually perceived. Thus, it may be visually determined whether portions of the surface 118 have been roughened and/or whether contaminants have been removed in certain areas on the surface 118.

FIG. 1B is a schematic top view of a portion of PCBA100 of FIG. 1A. Specifically, fig. 1B shows a portion of PCBA100 indicated by circle 1B in fig. 1A. In fig. 1B, the opto-electronic component 108, the coupling area 110, and the laser roughened area 112 are shown in more detail. As described above, the laser-roughened area 112 may be positioned entirely within the coupling area 110. In the illustrated configuration, the laser-roughened area 112 is concentrically positioned within the coupling area 110, although other configurations may be implemented. Opto-electronic component 108 may be electrically coupled to other components of PCBA100 by electrically conductive couplings 106 a-106 d.

As mentioned, the optical component may comprise a lens. In some configurations, the optical components may partially or fully enclose components positioned in the following regions 114: the region 114 is located inside the coupling region 110. For example, the optical component may define a cavity to enclose the optoelectronic component 108 between the optical component and a PCB of the PCBA 100. In such a configuration, the optical components may hermetically seal the optoelectronic components 108 or other components positioned in the region 114. Laser-roughened area 112 and/or coupling area 110 may surround opto-electronic component 108 in a plane defined by the PCB of PCBA 100. Additionally, the optical component may optionally be optically aligned with the optoelectronic component.

In some configurations, PCBA100 of fig. 1A-1B may be implemented as an optoelectronic component employing the PCBA. For example, PCBA100 can be implemented as an optoelectronic module for use in a transceiver, Transmitter Optical Subassembly (TOSA), Receiver Optical Subassembly (ROSA), active optical cable, and the like. In some configurations, the photovoltaic module may conform to the form factor (form factor) of Gen4 QSFP or Gen4 QSFP +.

FIG. 1C is a schematic top view of a portion of PCBA 100. Specifically, FIG. 1C shows a portion of PCBA100 indicated by rectangle 1C in FIG. 1B. In fig. 1B, the coupling region 110 and the laser roughened region 112 are shown in more detail. As shown, the laser-roughened area 112 can overlie or be positioned on the coupling area 110. In the configuration shown, the laser roughened area 112 may be smaller than the coupling area 110. In some configurations, the laser roughened area 112 may be between about 50% and about 75% of the size of the coupling area 110, although other configurations may also be implemented. In other configurations, the size of the laser-roughened area 112 can be substantially equal to or greater than the size of the coupling area 110. Further, the laser-roughened area 112 may not be positioned entirely within the coupling area 110. In such a configuration, the laser roughened area 112 may partially overlap the coupling area 110.

Fig. 2A is a cross-sectional schematic view of a portion of a PCB of PCBA 100. In fig. 2A, the laser roughened area 112 is shown in more detail. As described above, a laser may be used to increase the roughness of surface 118 of PCBA100 and/or to remove a portion of PCBA 100. As shown in fig. 2A, PCBA100 may include a layer 116 positioned on substrate 102 and defining a surface 118 of PCBA 100. A laser can be applied to the surface 118 to remove a portion of the layer 116, thereby forming the laser roughened area 112. In the configuration shown, only a portion of layer 116 is removed to form laser roughened area 112. However, in other configurations, the entire layer 116 may be removed to form laser-roughened area 112, or additional layers (not shown) may be removed from PCBA 100. In some configurations, layer 116 may be a solder mask layer or a portion of a solder mask. Thus, the solder mask can be a cleaned and/or roughened portion of PCBA 100. There may be no solder mask present at the laser roughened area 112 of the PCB or PCBA 100.

Fig. 2B is a cross-sectional schematic view of a portion of PCBA 100. Specifically, fig. 2B shows: a surface 118, indicated at 118a, of PCBA100 prior to application of the laser light, and a surface 118, indicated at 118b, of PCBA100 after application of the laser light. As shown, the surface 118a prior to application of the laser light is relatively smooth. In such a case, the adhesive used to bond, for example, the optical component to surface 118a may bond poorly, which may result in a relatively weak bond that may fail prematurely. In contrast, as shown, surface 118b is rougher after the laser is applied. In this case, the adhesive used to bond the optical component (as described with reference to fig. 1A-1C) to the surface 118b may form a stronger bond between the optical component and the PCB than the smooth surface 118 a. Although any suitable adhesive may be used for bonding, in some configurations, an epoxy may be applied.

One measure of surface roughness is the arithmetic mean deviation of the estimated profile of the surface or the average roughness of the profile of the surface, denoted R_a. In one example, R of surface 118a_aRoughness may be less than 0.2 μm, and R of surface 118b_aThe roughness may be greater than 0.3 μm. Thus, the laser may increase the roughness of the surface 118 by at least 0.1 μm R_a. However, in other cases, the surfaces 118a, 118b may have other roughness values. For example, surface 118 of PCBA100 may have any suitable roughness value. Further, a laser may be used to increase the roughness of the surface 118 by a value less than or greater than the example values described above.

Fig. 3 is a flow diagram of an example method 300 of forming a PCBA and/or modifying a surface of a PCB. Method 300 may be implemented in the construction of a component that includes a PCB, such as PCBA100 of FIGS. 1A-1B. Although shown as discrete blocks, the various steps in fig. 3 may be divided into other steps, combined into fewer steps, or omitted, depending on the desired implementation.

the method 300 may begin at step 302, and in step 302, a substrate may be provided. For example, the substrate 102 of fig. 1A-1B may be provided. At step 304, a conductive coupling can be formed on a surface of a substrate. For example, referring to fig. 1A to 1B, conductive couplings 106a to 106e may be formed on a surface of the substrate 102. Any suitable configuration may be used to form the conductive coupling. For example, a layer of conductive material, such as a copper layer, may be positioned on a substrate, which may be non-conductive. The conductive material may be etched or otherwise processed to remove a portion of the conductive material, and the remaining conductive material may form a conductive coupling on the surface of the substrate.

At step 306, one or more components may be coupled to the surface of the substrate. In some configurations, the component may be an electrical component and/or an optoelectronic component. For example, referring to fig. 1A-1B, electrical components 104 a-104 e and/or optoelectronic component 108 may be coupled to surface 118 of substrate 102. Thus, at least one optoelectronic component may be coupled to a surface of the PCB. In some configurations, the component may be soldered to a conductive coupling of the PCB, thereby mechanically coupling the component to the PCB and electrically coupling the electrical component to the conductive trace.

At step 308, a solder mask may be applied over the substrate and/or the conductive coupling. The solder mask may be applied using any suitable technique. For example, in some configurations, a solder mask may be applied using a masking or screen printing technique. The solder mask may be applied as an epoxy liquid onto the surface of the PCB (e.g., onto the substrate and/or conductive coupling) by screen printing a pattern or mask. Additionally or alternatively, the solder mask may be applied using any suitable technique, such as a Liquid Photoimageable Solder Mask (LPSM) or a dry film photoimageable solder mask (DFSM). Once applied, the solder mask may be cured, for example, using a thermal curing process or an ultraviolet curing process. Any suitable process, such as photolithography, may be used to form the openings in the solder mask. In some configurations, the solder mask may form a surface of the PCB, but in other configurations, the solder mask may not be included in the PCB.

At step 310, a laser may be applied to a surface of a substrate or PCB (e.g., laser processing the surface). The laser may be applied to a specific area on the surface of the PCB. For example, the laser may be applied to a portion of the PCB that may need to have contaminants removed or decomposed. In another example, the laser may be applied on a portion of the PCB that may require increased surface roughness. In particular, the laser may be applied to a portion of a surface of the PCB to which components of the PCB are to be coupled. In some configurations, the component to be coupled to the surface of the PCB may be an optical component. The area to which the laser is applied may be a laser-roughened area, such as laser-roughened area 112, and the area where the component is coupled to the PCB may be a coupling area, such as coupling area 110. As shown, for example, in fig. 1A-1C, the shape of the laser-roughened area may correspond to the shape of the coupling area, and in some configurations, the laser-roughened area is smaller than the coupling area.

The application of the laser (e.g., laser treatment) may remove at least a portion of a layer of the PCB and/or may increase the roughness of the surface of the printed circuit board. In some aspects, the laser may increase an arithmetic mean deviation of the evaluation profile of the surface of the printed circuit board by at least 0.1. In addition, the laser may decompose or remove contaminants from the surface of the PCB. The laser may improve the coupling of the optical component to the printed circuit board by increasing the roughness of the surface of the printed circuit board and/or removing contaminants from the surface of the printed circuit board. In configurations where a solder mask is applied to a surface of a PCB, a laser may remove at least a portion of the solder mask on the PCB.

The characteristics of the laser, such as the power, intensity, and wavelength of the laser, may be selected to be high enough to increase the roughness of the surface and/or remove contaminants without damaging the PCB and/or components coupled to the PCB. The desired power, intensity, and wavelength of the laser may depend on the materials included in the PCB (e.g., layers of the PCB), the materials of the contaminants, the materials of the components coupled to the PCB, or any suitable combination thereof. In one example, the laser may be an ultraviolet laser, such as a laser that emits electromagnetic radiation falling within a range of ultraviolet wavelengths. In some cases, the ultraviolet wavelengths may include wavelengths between about 100 nanometers (nm) and about 400 nm. In some configurations, the laser may be a laser having a wavelength of about 355nm, although other suitable configurations may also be implemented. Additionally or alternatively, in some configurations, the laser may include a laser power of about 3 watts (W).

The operation of the laser may be controlled manually or may be automatically controlled using a controller. The controller may specify the location on the substrate or PCB where the laser is to be applied. For example, the pattern laser applied on the substrate or PCB may correspond to the laser roughened area 112 (see fig. 1A to 1C). Thus, the pattern can be selected such that the laser forms the laser roughened area 112. In some configurations, the laser may be precisely controlled to form the laser roughened area 112 in a particular area on the surface of the substrate or PCB.

At step 312, a visual inspection of the surface of the substrate or PCB may be performed. Applying a laser to the surface of a substrate or PCB may significantly (visibly) modify the surface in the area to which the laser is applied. In particular, the laser may be applied for a sufficient time and duration to decompose the surface of the PCB such that the laser-roughened area (e.g., laser-roughened area 112) is visually perceptible. Therefore, by visually inspecting the surface, it is possible to determine: whether a portion of the PCB has been laser treated, whether contaminants have been removed from a particular area on the surface, and whether that area has been roughened. For example, the laser may change the color or texture of the surface to which the laser is applied. In particular, the color or texture of the surface may be different in this region, since all or part of the layer may be removed by the laser. Such a configuration may also facilitate positioning of the component to be coupled to the surface, as a distinctly modified surface may indicate the location at which the component should be attached to the surface.

Additionally or alternatively, visual inspection of the surface may aid in determining: whether the laser was successfully applied to the surface, whether the contaminants were removed in specific areas of the surface, and whether specific areas of the surface were roughened. In such a configuration, the component may be coupled to the surface in areas where contaminants have been removed and/or areas that have been laser roughened.

At step 314, another component may be coupled to a surface of the substrate or PCB. The component may be coupled to the surface at the coupling area and/or at the laser-roughened area formed by applying the laser. In some configurations, the component may be an optical component, such as a lens, but the concepts described herein may also be applied to other types of components. The component may be attached on a surface of the PCB at the coupling area, and the laser roughened area may be positioned at least partially or completely inside the coupling area. The component may be coupled to the surface in any suitable manner, and in some configurations, an adhesive, such as an epoxy, may be used. Where the component is an optical component, the optical component may be optically aligned with one or more optoelectronic components coupled to the surface.

in some configurations, the optical component may at least partially enclose the optoelectronic component after the optical component is coupled to the PCB. Additionally or alternatively, the optical component may hermetically seal the optoelectronic component between the PCB and the optical component. Thus, after the optical component is coupled to the PCB, the optoelectronic component may be hermetically sealed between the PCB and the optical component.

In some configurations, the method 300 may include: at least one electrical component, such as electrical components 104 a-104 e of fig. 1A-1B, is attached to a surface of a substrate or PCB. In some configurations, the electrical component may be coupled prior to applying the laser, but in other embodiments, the laser may be applied prior to coupling the electrical component, or the laser may be applied substantially simultaneously with coupling the electrical component. The electrical components may be electrically coupled by conductive couplings such as traces, pads, and/or other features etched from one or more layers of conductive material such as copper. In some configurations, the electrical component may be soldered to electrically and mechanically couple to a substrate or PCB.

Those skilled in the art will appreciate that for the above-described processes and methods and other processes and methods disclosed herein, the functions performed in the processes and methods may be performed in a different order. Further, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into other steps and operations without departing from the disclosed embodiments.

Fig. 4 is a flow diagram of an example method 400 of forming a PCBA, such as PCBA100 of fig. 1A-1B, and/or modifying a surface of a PCB. Method 400 may include any suitable aspect of method 300, or method 300 may include any suitable aspect of method 400. Although shown as discrete blocks, the various steps in fig. 4 may be divided into other steps, combined into fewer steps, or omitted, depending on the desired implementation.

The method 400 may begin at step 402, where one or more optoelectronic components may be coupled to a surface of a PCB in step 402. For example, the optoelectronic component 108 of fig. 1A-1B may be coupled to a surface of a PCB. Thus, at least one optoelectronic component may be coupled to a surface of the PCB. In some configurations, the optoelectronic component may be soldered to a conductive coupling of the PCB, thereby mechanically coupling the optoelectronic component to the PCB and electrically coupling the electrical component to the conductive trace.

At step 404, the surface of the PCB may be laser treated to form laser roughened areas on the surface of the PCB. The laser may be applied to a specific area on the surface of the PCB. For example, the laser may be applied to portions of the PCB that may require removal of contaminants and/or increase the roughness of the surface. In particular, the laser may be applied to a portion of the surface of the PCB to which components of the PCB are to be coupled. The area to which the laser is applied may be a laser roughened area, and the area where the component is coupled to the PCB may be a coupling area. The shape of the laser roughened area may correspond to the shape of the coupling area. In some configurations, the laser roughened area is smaller than the coupling area. The laser roughened area may surround the optoelectronic component in a plane defined by the PCB.

The laser may remove at least a portion of a layer of the PCB and/or may increase the roughness of the surface of the PCB. In some aspects, the laser may increase an arithmetic mean deviation of the evaluation profile of the surface of the PCB by at least 0.1. In addition, the laser may remove contaminants from the surface of the PCB. The laser may improve the coupling of the optical component to the printed circuit board by increasing the roughness of the surface of the printed circuit board and/or removing contaminants from the surface of the printed circuit board. In some configurations, a solder mask may be applied to the PCB prior to laser processing. In this configuration, the laser may remove at least a portion of the solder mask on the PCB.

the power, intensity, and/or wavelength of the laser may be selected to be high enough to increase the roughness of the surface and/or remove contaminants without damaging the PCB and/or components coupled to the PCB. The desired power, intensity, and/or wavelength of the laser may depend on the materials included in the PCB (e.g., layers of the PCB), the materials of the contaminants, the materials of the components coupled to the PCB, or any suitable combination thereof. In one example, the laser may be an ultraviolet laser, such as a laser that emits electromagnetic radiation falling within a range of ultraviolet wavelengths. In some cases, the ultraviolet wavelengths may include wavelengths between 100 nanometers (nm) and 400 nm. In some configurations, the laser may be a 355nm wavelength laser, although other suitable configurations may also be implemented. Additionally or alternatively, in some configurations, the laser may include a laser power of 3 watts (W).

In some configurations, a visual inspection of the surface of the substrate or PCB may be performed. Applying the laser to the surface of the substrate or PCB may significantly modify the surface in the area to which the laser is applied. In particular, the laser may be applied for a sufficient time and duration to decompose the surface of the PCB such that the laser roughened area is visually perceptible. Therefore, by visually inspecting the surface, it is possible to determine: whether a portion of the printed circuit board has been laser treated, whether contaminants have been removed from a particular area on the surface, and/or whether the area has been roughened. For example, the laser may change the color or texture of the surface to which the laser is applied. In particular, the color or texture of the surface may be different in this region, since all or part of the layer may be removed by the laser. Such a configuration may also facilitate positioning of the component to be coupled to the surface, as a distinctly modified surface may indicate the location at which the component should be attached to the surface.

Additionally or alternatively, visual inspection of the surface may aid in determining: whether the laser was successfully applied to the surface, whether contaminants were removed in specific areas of the surface, and/or whether specific areas of the surface were roughened. In such a configuration, the component may be coupled to the surface in areas where contaminants have been removed and/or areas that have been laser roughened.

At step 406, an optical component may be coupled to a surface of the PCB. The optical component may be coupled to the surface at the coupling area and/or at the laser-roughened area formed by applying the laser. In some configurations, the optical component may be a lens, but the concepts described herein may be applied to other types of components. The optical component may be attached on a surface of the printed circuit board at the coupling area, and the laser roughened area may be positioned at least partially or completely inside the coupling area. The optical component may be coupled to the surface in any suitable manner, and in some configurations, an adhesive may be used. In some cases, the optical component may be optically aligned with one or more optoelectronic components coupled to the surface.

Fig. 5A-5B illustrate an optical component 550 coupled to a surface of PCBA 100. In particular, fig. 5A is a schematic top view of PCBA100 with optical component 550, and fig. 5B is a schematic side view of PCBA100 with optical component 550 coupled to a surface. In some configurations, optical component 550 may be coupled to a surface of PCBA100 at coupling area 110 and/or at laser-roughened area 112 formed by application of a laser (see fig. 1A). In some configurations, optical component 550 may be a lens, but the concepts described herein may be applied to other types of components. Optical component 550 may be attached on a surface of PCBA100 at the coupling area, and the laser-roughened area may be positioned at least partially or completely inside the coupling area. Optical component 550 may be coupled to a surface in any suitable manner, and in some configurations an adhesive may be used. In some cases, optical component 550 may be optically aligned with one or more optoelectronic components coupled to the surface.

In some configurations, optical component 550 may at least partially enclose an optoelectronic component, such as optoelectronic component 108 of fig. 1A, after optical component 550 is coupled to PCBA 100. Additionally or alternatively, the optical component 550 may hermetically seal the optoelectronic component between the PCBA and the optical component 550. Thus, after optical component 550 is coupled to PCBA100, optoelectronic component 108 of fig. 1A may be hermetically sealed between PCBA100 and optical component 550. The optical component 550 may be a lens optically coupled or aligned with the optoelectronic component 108.

In some configurations, at least one electrical component, such as electrical components 104 a-104 e of fig. 1A-1B, may be attached to a surface of the PCB. In some configurations, the electrical components may be coupled prior to application of the laser, although any suitable configuration may be implemented. The electrical components may be electrically coupled by conductive couplings such as traces, pads, and/or other features etched from one or more layers of conductive material such as copper. In some configurations, the electrical component may be soldered to electrically and mechanically couple to a substrate or PCB.

In some cases, laser treatment of the surface of a substrate or PCB may improve bonding between the component and the surface. In particular, the laser may improve the coupling of the optical component to the printed circuit board by increasing the roughness of the surface of the printed circuit board and/or removing contaminants from the surface of the printed circuit board. This configuration may improve bonding when an adhesive is used; similarly, such a configuration may also be advantageous in other binding mechanisms. Further, the configurations described herein may be used to avoid weak bonds formed, for example, by contamination and/or smooth surfaces of the substrate or PCB.

When the described concept is implemented to bond an optical component to a PCB, the resulting bond may securely fix the optical component to the PCB. Furthermore, by removing any contaminants from the surface of the PCB to which the optical components of the PCB are bonded, weak bonds can be avoided. In this case, the bond formed may be stronger and therefore not break over time. A stronger bond may be useful during subsequent processing of the PCB to form the optoelectronic assembly because the bond does not break during handling or subsequent processing. Additionally or alternatively, the stronger bond does not break after the photovoltaic module is manufactured, for example, during operation of the photovoltaic module. This configuration may also prevent premature failure of the optoelectronic assembly, as weak bonds caused by smooth surfaces or contaminants on the surface of the PCB may be avoided.

Although the described configuration may be particularly advantageous for bonding optical components to a PCB, in other configurations, the concepts described herein may also be applied to improve bonding between any component, e.g., an electrical component or any other component that may be bonded to a PCB, and the PCB.

The terms and expressions used in the specification and claims are not limited to the written meaning but are used only to enable a clear and consistent understanding of the disclosure. It is understood that the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "component surface" includes reference to one or more of such surfaces.

As used herein, "electrical component" refers to a component that involves electricity, "optical component" refers to a component that involves electromagnetic radiation (e.g., visible light or otherwise), and "opto-electrical component" refers to a component that involves both electrical and optical signals, and/or the conversion of an electrical signal to an optical signal or vice versa.

The term "substantially" means: the recited characteristic, parameter, or value need not be implemented precisely, but deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations, and other factors known to those skilled in the art, may occur in amounts that do not preclude the effect that the characteristic is intended to provide.

Aspects of the present disclosure may be embodied in other forms without departing from the spirit or essential characteristics thereof. The described aspects are to be considered in all respects only as illustrative and not restrictive. The claimed subject matter is indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A method of modifying a surface of a printed circuit board in a photovoltaic assembly, the method comprising:

Coupling at least one optoelectronic component to the surface of the printed circuit board;

Laser treating the surface of the printed circuit board to form a laser roughened area on the surface of the printed circuit board; and

Coupling an optical component to the printed circuit board at the laser-roughened area on the surface of the printed circuit board.

2. The method of claim 1, wherein the optical component is attached at a coupling area on the surface of the printed circuit board and the laser roughened area is positioned at least partially within the coupling area.

3. The method of claim 1, wherein the laser treatment removes at least a portion of a layer of the printed circuit board.

4. the method of claim 1, wherein the laser treatment increases the roughness of the surface of the printed circuit board at the laser roughened area.

5. The method of claim 1, wherein the laser treatment increases an arithmetic mean deviation of an evaluation profile of the surface of the printed circuit board by at least 0.1.

6. The method of claim 1, wherein the laser treatment removes contaminants from the surface of the printed circuit board.

7. The method of claim 1, wherein the laser treatment improves coupling of the optical component to the printed circuit board by increasing roughness of the surface of the printed circuit board and/or removing contaminants from the surface of the printed circuit board.

8. The method of claim 1, wherein the optical component is coupled to the printed circuit board using an adhesive.

9. The method of claim 1, further comprising applying a solder mask to the surface of the printed circuit board prior to the laser processing, wherein the laser processing removes at least a portion of the solder mask on the printed circuit board.

10. The method of claim 1, wherein the optical component is a lens optically coupled to the optoelectronic component, wherein the lens is optically aligned with the optoelectronic component.

11. The method of claim 1, wherein the laser roughened area surrounds the optoelectronic component in a plane defined by the printed circuit board, and the optical component at least partially encloses the optoelectronic component after the optical component is coupled to the printed circuit board.

12. The method of claim 1, wherein the optoelectronic component is hermetically sealed between the printed circuit board and the optical component after the optical component is coupled to the printed circuit board.

13. The method of claim 1, further comprising attaching at least one electrical component to the surface of the printed circuit board.

14. The method of claim 1, wherein the laser is applied for a sufficient duration to decompose a surface of the printed circuit board such that the laser-roughened area is visually perceptible, the method further comprising visually inspecting the surface of the printed circuit board to determine whether a portion of the printed circuit board has been laser treated.

15. An optoelectronic assembly comprising:

a printed circuit board;

At least one optoelectronic component coupled to a surface of the printed circuit board; and

An optical component attached to the laser roughened area of the surface of the printed circuit board by an adhesive, the optical component being optically aligned with the optoelectronic component.

16. the optoelectronic assembly of claim 15, wherein the laser roughened area of the surface of the printed circuit board is rougher than the remaining area of the surface of the printed circuit board.

17. The optoelectronic assembly as recited in claim 16, wherein the laser roughened area of the surface of the printed circuit board has a greater arithmetic mean deviation of an evaluation profile than a remainder of the surface of the printed circuit board.

18. The optoelectronic assembly as recited in claim 16, wherein a difference between the laser roughened area and a remainder of the surface of the printed circuit board is visually perceptible.

19. The optoelectronic assembly of claim 15, further comprising a solder mask on the surface of the printed circuit board, wherein the solder mask is absent at the laser roughened area of the surface of the printed circuit board.

20. The optoelectronic assembly of claim 15, wherein the laser roughened area surrounds the optoelectronic component in a plane defined by the printed circuit board, the optical component is a lens at least partially enclosing the optoelectronic component, the lens is optically aligned with the optoelectronic component, and the lens hermetically seals the optoelectronic component.